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Shaped zeolites Y for polypropylene cracking
No full textInternational audienceThis study focuses on chemical interactions occurring between commercially available FAU zeolites, with various Si/Al ratios (Si/Al = 2.5, 6, and 31), micro- and mesoporosity, acidic properties, and a γ-Al2O3 used as a binder to produce extrudates. The extrudates are characterised by conventional techniques that provide information on their structure, texture, and acidic features and are compared to their parent powders. The catalytic performances of the zeolite powders, their derived alumina extrudates, and physical mixtures of zeolites/γ-Al2O3 are evaluated in polypropylene catalytic cracking. A detailed thermogravimetric and spectroscopic (operando FT-IRGC-MS) analysis of the reaction, including catalyst coking and regeneration, shows the emergence of rules to design fit-for-purpose catalysts. IR spectroscopy-derived number, nature, and strength of the acid sites are consistent with the catalytic results, highlighting the role of new catalytic sites located on the external or mesoporous surfaces of the zeolites, i.e., at the zeolite-binder interface. This illustrates that binding and subsequent thermal treatment of zeolite powders to produce industrially relevant catalysts determine the quality and quantity of active sites not always present in pure powders, typically reported in the open literature. During the shaping process, neither the strength nor accessibility of the native zeolite acid sites are affected, but chemical interactions between γ-Al2O3 and the zeolite generate new Brønsted acid sites, increasing catalytic performances in polypropylene cracking. This study is also a blueprint for other zeolites/binders forming processes (spraydrying, oil-dropping, pelletising) and could also be influential in shaping adsorbents. It is remarkable that, despite a significant dilution (50 %) of USY zeolites with γ-Al2O3, no significant change in catalytic activity is observed while the newly created sites improve selectivity towards lighter hydrocarbons
Geographic Information System-Based Database for Monitoring and Assessing Mining Impacts on Water Resources and Environmental Systems at National Scale: A Case Study of Morocco (North Africa)
No full textInternational audienceDecision-making in how to manage environmental issues around mine sites is generally a complicated task. Furthermore, the large amount of data and information involved in the management process is cumbersome. However, Decision Support Tools (DSTs) based on Geographic Information Systems (GISs) are of great interest to environmental managers in order to help them to make well-informed and thoroughly documented decisions regarding reclamation plans, especially for abandoned mine sites. The current study highlights the implementation of a cost-effective and efficient GIS-based database as a DST that will be used to assess and manage environmental challenges, particularly those related to water resources, such as hydrographic network issues surrounding mine sites. Based on GISs, a prototype of a national geodatabase was designed and implemented for Moroccan mine sites. It consisted of a set of GIS layers that facilitated the dissemination of an extensive array of multidisciplinary environmental data concerning Moroccan mines to decisionmakers. By applying GIS tools, such as buffer zone analysis, to environmental and hydrological datasets, high-priority mines requiring urgent intervention were identified based on their proximity to water resources, their acid mine drainage (AMD) potential, and their environmental impact on ecosystems. The results highlight the effectiveness of GIS-based approaches in assessing environmental risks, particularly concerning water resources, while also contributing to sustainable mining management in Morocco. Finally, using the GIS-based database is expected to raise the awareness of decisionmakers in government agencies and mining companies for implementing a reclamation program for mine sites
Impact of Three Decades of Conservation Management Systems on Carbon Management Index and Aggregate Stability
No full textInternational audienceThe sustainability of agroecosystems depends on the maintenance of soil organic matter (SOM) and soil aggregate stability, which are key components of soil health. The long-term effects of conservation management systems, such as the adoption of no till (NT) associated with cover crops, on soil quality are still unclear. The aim of this study was to evaluate the long-term effects of NT systems combined with cropping systems ecologically intensified by the presence of legumes on the carbon management index (CMI) and the state of soil aggregation, as sensitive tools to assess the quality of soil management systems. NT combined with autumn and spring legume cover crops increased the proportion of soil aggregates > 2 mm, resulting in higher weighted average diameters and higher aggregation index values in comparison to conventional tillage (CT), which favored the soil microaggregate proportion. The soil C content was favored by NT only in the surface layer, while the use of legume cover crops increased the C stock by 23% compared to the system without legume cover crops in the 0-20 cm layer. In the topsoil under NT, the stocks of particulate organic matter (POM) and mineral-associated organic matter (MAOM) were 100% and 37% greater than in CT, respectively. A greater CMI was observed under NT compared to CT in systems with no legumes (18%), with one legume (52%), and with two legumes (72%) as cover crops. These results highlight no till's positive impact on soil health, further enhanced by the legume-based ecological intensification of cropping systems
Analyses de productions de figurines en terre cuite antiques par p-XRF/LIBS : une complémentarité des techniques pour discriminer les ateliers ?
No full textInternational audienceLa ville d’Augustodunum, l’actuel Autun (Saône-et-Loire, 71) est, à la fin du IIe - première moitiédu IIIe siècle apr. J.-C. un centre important de fabrication de figurines en série par moulage. Quatreateliers ont été fouillés et ont livré un abondant matériel de valves de moules et de déchets de production.Deux d’entre eux appartiennent à un même artisan, Pistillus. Ce dernier est connu par les nombreuses signatures apposées sur les moules, mais également sur les figurines, notamment des déesses-mères, des Vénus, des bustes ou des cucullatus. Une thèse de doctorat est en cours sur les modalités des productions de coroplastie à Autun et plus particulièrement celles de Pistillus (L. Androuin). Pour compléter les recherches iconographiques, typologiques et archéologiques de ces objets, et afin d’étudier les possibilités de discrimination des ateliers entre eux, un programme d’analyses physico-chimiques est mis en oeuvre à partir de la sélection d’échantillons issus de trois ateliers : celui de la rue des Pierres (fouille 1987) et deux du secteur artisanal de la Genetoye (fouille 2014 et 2019/2020). Cet échantillonnage, comprenant un même nombre de fragments, a été analysé en utilisant deux techniques non invasives, la fluorescence- X portable (p-XRF) et la spectrométrie sur plasma induit par laser également portative (LIBS SciAps Z-903). Ces résultats ont ensuite été comparés avec ceux obtenus par spectrométrie optique à plasma à couplage inductif (ICP-OES) après un prélèvement sur les mêmes échantillons. L’objectif de ce projet est d’explorer en plus des possibles discriminations des différents ateliers d’Autun, le potentiel de ces techniques non destructives et leur utilisation dans les études des origines de fabrication de terre cuite àtexture fine
Un cas d’encéphalite limbique féline
No full textInternational audienceA 4.5-year-old neutered male cat was presented with recurrent manifestations suggesting focal seizures associated with behavioral changes. MRI of the brain, analysis of cerebrospinal fluid, and electroencephalographic examination were suggestive of limbic encephalitis, although they could not confirm it with certainty. Limbic encephalitis was definitively confirmed through post-mortem histopathological examination combined with specific serum testing for anti-LGI1 antibodies. Feline limbic encephalitis with anti-LGI1 (EL-LGI1) is a form of autoimmune encephalitis recently recognized in cats, possibly caused by antibodies targeting the LGI1 protein. Similar to its human form, EL-LGI1 in cats manifests as focal seizures, often accompanied by oro-facial automatisms and behavioral changes such as aggression. The diagnosis relies on the detection of anti-LGI1 antibodies, although this test is not routinely available in veterinary medicine, especially in France. This case illustrates a typical example of limbic encephalitis for which a definitive diagnosis was established post-mortem and highlights the challenges of pre-mortem diagnosis.Un chat mâle castré de 4,5 ans a été présenté pour des manifestations récurrentes évoquant des crises épileptiques focales associées à une modification du comportement. L’examen IRM de l’encéphale, l’analyse du liquide cérébrospinal, et l’examen électroencéphalographique étaient évocateurs d’une encéphalite limbique, sans pour autant permettre de l’affirmer avec certitude. L’encéphalite limbique a pu être confirmer avec certitude grâce à l’examen anatomopathologique post-mortem couplé au dosage sérique spécifique des anticorps anti-LGI1. L’encéphalite limbique féline à anticorps anti-LGI1 (EL-LGI1) est une forme d’encéphalite auto-immune, récemment reconnue chez les chats, possiblement causée par des anticorps ciblant la protéine LGI1. Similaire à sa forme humaine, l’EL-LGI1 chez les chats se manifeste par des crises épileptiques focales, souvent accompagnées d’automatismes orofaciaux et de changement de comportement comme l’agressivité. Le diagnostic repose sur la détection des anticorps anti-LGI1, bien que ce dosage ne soit pas disponible en routine en médecine vétérinaire et particulièrement en France. Ce cas illustre un cas typique d’encéphalite limbique pour lequel un diagnostic a été établi avec certitude en post-mortem et souligne la difficulté du diagnostic pré-mortem
Bélatacept en conversion précoce post-transplantation rénale : état des lieux et avis d’experts
No full textInternational audienceThe standard immunosuppressive treatment after organ transplantation typically includes a calcineurin inhibitor (tacrolimus or cyclosporine A), an antimetabolite (mycophenolic acid) or an mTOR inhibitor, and corticosteroids. However, these treatments are associated with multiple side effects, including nephrotoxicity. Belatacept, a fusion protein blocking the CD80/86 costimulation pathway, emerges as an effective and well-tolerated alternative. Initial phase III studies showed that de novo belatacept improves renal function and reduces the incidence of donor-specific antibodies, despite a higher rate of acute cellular rejections. Early conversion studies (within the first 6 months post-transplantation) demonstrate significant improvement in renal function, particularly when conversion is performed early. However, the risk of acute rejection and opportunistic infections must be monitored. This article summarizes the available studies on early conversion to belatacept in kidney transplanted patients
Cold Agglutinin Syndrome Secondary to Mycoplasma pneumoniae Infection in Adults: Results From a Large French Observational Study (MyCOLD Study).
No full textInternational audienceMycoplasma pneumoniae (MP), primarily a respiratory pathogen, can cause extra-pulmonary manifestations including cold agglutinin syndrome (CAS). We conducted a national, multicenter, observational, ambispective study to describe the characteristics, risk factors, and outcomes of MP-associated CAS. Adult patients hospitalized for a MP-infection with CAS (hemolytic anemia with hemoglobin 10 g/dL off therapy. We also compared MP-infected patients with or without CAS. Sixty patients (51.7% of females; median age of 48.5 years) were included. CAS was diagnosed a median of 10 days after MP-infection symptoms onset. At diagnosis, the median hemoglobin level was 6.9 g/dL, and 71.7% of patients received red blood cell transfusions. Intensive care unit (ICU) admission was required in 45% of patients, and 16.7% experienced a venous thromboembolic event (VTE). Seventeen patients (28.3%) received glucocorticoids alone, while 40 (66.7%) did not receive any specific treatment for CAS. After a median follow-up of 56 (30–83) days, 90% of patients achieved recovery, while 2 patients (3.3%) died from sepsis and pulmonary embolism. Glucocorticoid use did not significantly impact the rate or timing of recovery. Compared with MP-infected patients from the MYCADO cohort study (n = 1267), CAS patients had significantly more VTE (p < 0.0001) and ICU admissions (p = 0.03). MP-associated CAS typically occurs 10 days after the first symptoms of MP infection and is associated with ICU admissions and VTE. Overall, the prognosis of CAS is good, and glucocorticoids do not appear to influence outcomes
“Note sur la situation géopolitique actuelle du Pérou”
No full textExpertise pour la Cour Nationale du Droit d’Asile (CNDA), Paris.“Note sur la situation géopolitique actuelle du Pérou” Expertise pour la Cour Nationale du Droit d’Asile (CNDA), Paris, 22 février 2025
Quebrar el orden del espacio público. Los púlpitos de la discordia en Filipinas (siglos XVI-XVII)
No full textInternational audienceThis paper analyzes the role of the clergy in disrupting the established order in the Philippine archipelago during the 16th and 17th centuries through preaching. Although pulpits were traditionally used to maintain social order, recent studies have shown how some preachers challenged established norms and even led protest movements. Thus, this work not only examines a wide range of conflicts generated from the pulpits but also explores how authorities managed to silence these rebellious preachers settled in the Pacific.El presente trabajo analiza cómo el clero, por medio de la predicación, participó en la ruptura del orden establecido en el archipiélago filipino durante los siglos XVI y XVII. Aunque tradicionalmente los púlpitos se usaban para mantener el orden social, recientes estudios han demostrado cómo algunos predicadores desafiaban las normas establecidas e incluso lideraban movimientos de protesta. Así, este trabajo, no solo estudia un amplio abanico de situaciones de conflictividad generada desde los púlpitos sino que examina el modo en que las autoridades lograron silenciar a estos predicadores rebeldes, asentados en el Pacífico